The invention relates to automotive fuel systems, and more particularly to a fuel injection system for supplying fuel to an internal combustion engine.
It is known to use fuel injectors to inject fuel from a fuel rail into an engine intake manifold. Typically, the fuel inlet end of the fuel injectors communicates with a fuel rail, which supplies fuel to the injectors. The fuel outlet end of the fuel injectors is supported in an air intake manifold, which mixes the fuel with the proper amount of air prior to combustion. The fuel injectors must be long enough to bridge the gap between the fuel rail and the intake manifold. Fuel injectors come in a variety of standard lengths to accommodate different fuel system envelopes. One example of such a fuel injection system is seen in U.S. Pat. No. 5,531,202.
These standard length fuel injectors include a functional portion that is required for the operation of the fuel injector. This functional portion is often relatively short with respect to the overall length of the injector. To obtain the necessary overall length, the fuel injector often includes an extension tube, an extended body portion, an extended needle valve assembly, an electrical connection extension and other added features or components. Adding length to the fuel injector increases the costs of the injector due to increased material usage and increased assembly costs.
In these typical fuel systems, the injectors are exposed to the harsh environment of an internal combustion engine. To protect the injectors from the environment it is necessary to overmold the fuel injectors with a protective layer or overmolding, typically a plastic. Overmolding the injector adds additional costs.
It is also known to mount a shorter fuel injector in a fuel rail and to mount the fuel rail directly to the intake manifold. This helps eliminate the costs associated with lengthening the fuel injector to bridge a gap between the fuel rail and the intake manifold. Additionally, housing the injector inside the fuel rail can eliminate the need for overmolding. The space required between the fuel rail and the intake manifold is also reduced, thereby reducing the overall packaging envelope for the fuel injection system. U.S. Pat. Nos. 5,718,206 and 5,172,671 illustrate two such prior art fuel injection systems.
In engines having two banks of cylinders, it is common to utilize two metallic fuel rail assemblies that are connected together at one end by a crossover tube providing fluid communication between the two fuel rail assemblies. The ends of the crossover tube are typically brazed to the opposing fuel rail assemblies to provide the necessary connections. The resulting fuel rail assembly is substantially U-shaped. It is also known to form an integral, non-metallic U-shaped fuel rail assembly for engines having two cylinder banks.
The present invention provides an improved module for packaging fuel injectors, and more preferably, for packaging only the functional portion of the fuel injectors between a fuel supply and an intake manifold. Extension tubes, extended body portions, extended needle valve assemblies, electrical connection extensions and any other features or components needed to elongate the injectors are eliminated, thereby greatly reducing the cost of the injectors. The improved fuel injector module is well-suited for use with engines having two banks of cylinders. A compact and preferably non-metallic module houses all of the injectors and electrical connections required for both cylinder banks. The injectors are substantially sealed from the environment, thereby eliminating the need for protective overmolding. Furthermore, the injector module can be directly attached to the intake manifold. Only a single fuel connection and a single electrical connection is required to supply fuel and power to all of the injectors in the injector module. The injector module can also be equipped with features to improve the atomization of fuel as it exits the fuel injectors.
More specifically, the invention provides a fuel injector module for an internal combustion engine having two banks of cylinders. The injector module includes a longitudinally extending central portion with opposing sides, at least two branches extending laterally from one of the opposing sides, and at least two more branches extending laterally from the other of the opposing sides. Each of the branches has therein an injector receptacle. A fuel injector is housed in each injector receptacle for injecting fuel into a respective cylinder.
In one aspect of the invention, each of the branches includes an electrical connector adjacent the respective injector receptacle for providing electrical power to the respective fuel injector. Preferably, each of the electrical connectors includes a pogo-pin electrically coupled to the respective fuel injector. In another aspect of the invention, the central portion houses a wire harness that is electrically coupled to each of the electrical connectors.
In yet another aspect of the invention, each branch includes a fuel feed passageway communicating with the respective injector receptacle. A fuel supply line communicates with each fuel feed passageway to supply fuel to each of the injectors. In another aspect of the invention, each branch includes an atomization chamber adjacent the outlet end of the fuel injector. An air supply passageway in the branch communicates with the atomization chamber and with an air supply line to supply air to the atomization chamber. The air supply improves the atomization of the fuel exiting the injector.
In an additional aspect of the invention, each branch includes a base portion and a cover portion. The fuel injector is sandwiched between the base portion and the cover portion. A seal member is also sandwiched between each respective base and cover portion to substantially seal the fuel injector from the environment.
The invention also provides a fuel injector module having improved electrical connections. The injector module includes a body portion, a fuel injector housed in the body portion, and a pogo-pin connector having a pogo-pin electrically coupled to the fuel injector to provide electrical power to the fuel injector. Preferably, the fuel injector includes two spaced-apart terminals, and the pogo-pin connector includes first and second pogo-pins. The first pogo-pin is electrically coupled to one of the terminals and the second pogo-pin is electrically coupled to the other of the terminals. The pogo-pin connector also preferably includes a housing that is movable with respect to the body portion to facilitate insertion and removal of the fuel injector from the body portion.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings.